This application claims the benefit of Korean Patent Application No. 2002-0034800, filed on Jun. 21, 2002, which is incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a pressure controllable packing enabling to control a pressure by making a fluid leak through a leakage path of the fluid provided in the packing if an inner pressure of a pressurization vessel exceeds a predetermined value.
2. Background of the Related Art
Generally, a packing is used for making a pressurization vessel airtight. Namely, an inner space of a vessel is sealed up from outside using a packing made of a flexible or elastic material so as to achieve a perfect coupling between the pressurization vessel and a cover or stopper.
There are various pressurization vessels for cookers such as a pressurization pan, a pressurization pot, a pressurization cooker, and the like. These vessels enable to cook by heating contents such as food and the like therein using a pressure higher than an atmospheric pressure. Such a pressurization vessel is exposed to explosion due to the increasing pressure inside the vessel by heating, whereby a safety valve is essential to be installed for safety. Yet, if hogwash sticks to the safety valve or degradation occurs in the safety valve used for a long term, the safety valve becomes out of order or broken down. Therefore, double or triple safety devices are required preferably.
The packing for the pressurization vessel according to the related art is mainly made of a silicon rubber as an elastic body. And, such a packing is installed so as to be contacted with an edge coupling portion between the cover and vessel body, whereby the packing adheres more closely to the edge coupling portion by an increasing force generated from the increasing pressure inside the vessel.
Accordingly, the present invention is directed to a pressure controllable packing that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a pressure controllable packing having a pressure controlling function by itself.
Another object of the present invention is to provide a pressure controllable packing of which portion is distorted if a pressure exceeds a predetermined value to lose the pressure through the distorted portion so as to have a pressure controlling function.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, in an elastic packing installed at a packing groove formed at an edge of a cover so as to isolate an inner space defined by a vessel and the cover from an outer space, a pressure controllable packing according to the present invention includes first and second rims pushed by a pressure of the inner space in directions tending to adhere closely to a surface of the packing groove and an edge surface of the vessel, a support part installed at a circumference end of the packing groove so as to be contacted with the circumference end and connecting the first and second rims to each other, and at least one long groove formed at a portion of the support part at which the first and second rims are connected to the support part, wherein the first or second rim at a portion where the long groove is formed is pushed in a circumferential direction so as to generate a distorted portion if a pressure of the inner space increases to exceed a predetermined value, and wherein a gap is generated from the distorted portion between surfaces of the first and second rim and the long groove or the edge surface of the vessel so as to reduce the pressure of the inner surface through the gap.
Preferably, a portion of the first or second rim to be placed in the long groove is narrower than a rest portion of the first or second rim, whereby the pressure can be controlled by adjusting a width of the portion.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.